package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.ScrollResult;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import static com.hmdp.utils.RedisConstants.BLOG_LIKED_KEY;
import static com.hmdp.utils.RedisConstants.FEED_KEY;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {
    @Resource
    private IUserService userService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private IFollowService followService;
    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List<Blog> records = page.getRecords();
        // 查询用户
        records.forEach(blog ->{
            this.queryBlogUser( blog);
            this.isBlogLiked(blog);
        });
        return Result.ok(records);
    }

    @Override
    public Result queryBlogById(Long id) {
        //1.查询blog
        Blog blog = getById(id);
        //2.查询blog有关的用户
        if (blog==null){
            return Result.fail("笔记不存在");
        }
        queryBlogUser( blog);
        //查询blog是否被点赞
        isBlogLiked(blog);

        return Result.ok(blog);
    }

    private void isBlogLiked(Blog blog) {
        //获取登录用户
        Long userId = UserHolder.getUser().getId();
        if (userId == null){
            return;
        }
        //判断当前用户是否已经点赞
        String key = "blog:liked:"+blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        blog.setIsLike(score!=null);
    }

    private void queryBlogUser(Blog blog) {
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }

    @Override
    public Result likeBlog(Long id) {
        //获取登录用户
        Long userId = UserHolder.getUser().getId();
        //判断当前用户是否已经点赞
        String key = "blog:liked:"+id;
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        //3.如果为点赞
        if (score == null){
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            if (isSuccess){
                stringRedisTemplate.opsForZSet().add(key,userId.toString(),System.currentTimeMillis());
            }
        }else {
            boolean isSuccess = update().setSql("liked = liked - 1").eq("id", id).update();
            if (isSuccess){
                stringRedisTemplate.opsForZSet().remove(key,userId.toString());
            }
        }
        //3.1数据库点赞数+1
        //3.2保存用户到redis集合

        //如果以点赞，取消点赞

        //4.1点赞数减1
        //4.2把用户从redis set集合内移除
        return null;
    }

    @Override
    public Result queryBlogLikes(Long id) {
        //查询top5

        Set<String> range = stringRedisTemplate.opsForZSet().range(BLOG_LIKED_KEY + id, 0, 4);
        if (range == null || range.isEmpty()){
            return Result.ok(Collections.emptyList());
        }
        //解析出用户id
        List<Long> ids = range.stream().map(Long::valueOf).collect(Collectors.toList());
        String join = StrUtil.join(",", ids);
        //根据用户id查询用户
        List<UserDTO> userDTOs = userService.query().in("id",ids).last("ORDER BY Field(id,"+join+")").list()
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());


        //返回用户
        return Result.ok(userDTOs);
    }

    @Override
    public Result saveBlog(Blog blog) {
        //获取登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        //保存探店笔记
        boolean isSuccess = save(blog);
        if (!isSuccess){
            return Result.fail("新增笔记失败");
        }
        //查询笔记作者的所有粉丝
        List<Follow> follows = followService.query().eq("follow_user_id", user.getId()).list();
        for (Follow follow : follows) {
            //获取粉丝id
            Long userId = follow.getUserId();
            //推送  （每一个粉丝都有自己的收件箱，每一个收件箱都是一个Sortedset）
            String key = FEED_KEY+ userId;
            stringRedisTemplate.opsForZSet().add(key,blog.getId().toString(),System.currentTimeMillis());

        }

        //返回id
        return Result.ok(blog.getId());
    }

    @Override
    public Result queryBlogFollow(Long max, Integer offset) {
        //1、找到收件箱，获取当前用户
        Long userId = UserHolder.getUser().getId();
        //2.查询收件箱
        String key = FEED_KEY+userId;
        Set<ZSetOperations.TypedTuple<String>> typedTuples = stringRedisTemplate.opsForZSet().reverseRangeByScoreWithScores(key,0,max,offset,2);
        //费控判断
        if(typedTuples == null || typedTuples.isEmpty()){
            return Result.ok();
        }
        //3.解析数据：blogId,score、offset
        List<Long> ids = new ArrayList<>(typedTuples.size());
        long minTime = 0;
        int os = 1;
        for (ZSetOperations.TypedTuple<String> typedTuple : typedTuples) {
            String idStr = typedTuple.getValue();
            ids.add(Long.valueOf(idStr));
            long time = typedTuple.getScore().longValue();

            if (time==minTime){
                os++;
            }else{
                minTime = time;//时间戳
                os = 1;
            }
        }
        //4.根据id查询blog
        String idStr = StrUtil.join(",", ids);
        List<Blog> blogs = query().in("id",ids).last("Order By FIELD(id,"+idStr+")").list();
        for (Blog blog : blogs) {
            queryBlogUser(blog);
            isBlogLiked(blog);
        }
        //5.封装并返回
        ScrollResult scrollResult = new ScrollResult();
        scrollResult.setList(blogs);
        scrollResult.setOffset(os);
        scrollResult.setMinTime(minTime);


        return Result.ok(scrollResult);
    }
}
